Polyvinyl Chloride Polymer Research Articles

Interaction Parameters of Some Polymers Used in Nuclear Power Plants with Ionizing Radiation, Produced Secondary Radiations and Radiation Damages

AbstractThe primary interactions of polypropylene (PP), poly(vinyl acetate) (PVA), ethylene‐vinyl acetate (EVA), polyvinyl chloride (PVC), polychloroprene (CR) and polyurethane (PUR) polymers preferred in the nuclear industry with gamma and neutron radiations, secondary radiations formed after neutron interactions and damages given to polymers by these ionizing radiations are investigated. The gamma interaction parameters Were determined in the photon energy range of 0.03‐20 MeV using WinXCOM, GEANT4 and FLUKA methods. Also, energy absorption and exposure buildup factors and Kerma parameters are calculated at different photon energies. To investigate the interactions of the studied polymers with neutron, the effective removal cross‐section for fast neutrons with theoretical and the partial neutron rates passing through the studied polymer at 4.5 MeV, 100 eV and 0.025 eV energies are determined with simulation codes. The numbers of secondary gamma‐rays and neutrons Were obtained with GEANT4. The Total Ionizing Dose and Displacements per Atom parameters are studied with the help of FLUKA simulation. It is observed that the interaction of PVC polymer with gamma radiation and PP polymer with neutron particles is higher than the others. The secondary radiation from PVC and CR is less. The PP, PVA, and EVA exhibit superior resistance to radiation damage.

Investigation of Microplastic Contamination in the Gastrointestinal Tract of Fish: A Comparative Study of Various Freshwater Species

The aqueous environment has been reported to be seriously threatened by the pollution of microplastics (MPs), which has been confirmed in numerous studies affecting various aquatic habitats. Despite this, few investigations exist on MP contamination in fish of specific regions. Thus, the current study aims to determine MP concentrations in the fish species of the Chhota Nagpur zone of eastern India. From August to September 2023, fish samples were collected from 10 km distance between two locations of Subarnarekha and Kharkai river banks through fishermen. Microplastics were found in the gastrointestinal tract of 45 fish of 8 species out of 48 samples. Of these species, six species were secondary consumers, while the remaining two were primary consumers. The average amount of microplastics consumed by each fish (n = 48) was 3.0 ± 1.8. A total of 144 microplastics were found in collected samples of fish species. Among the analyzed sample of MPs, 69.4% were fibers, films were (22.3%), and (8.3%) were fragments. The least contaminated species was T. ilisha (0.8 ± 0.7 particles/ind.), while L. rohita had the highest microplastic contamination (4.5 ± 1.7 particles/ind.). The present study found a negative correlation of - 0.83 between MP consumption and the mean body weight of fish. Similarly, a negative correlation of - 0.5 was found between the length of fish and MP intake. Polyamide (nylon), polypropylene, polyvinyl chloride, polycarbonate, polyethylene terephthalate, and polyethylene polymers were found. The size of MPs ranged from 45-355 μm and mainly were fibers. They were also predominantly blue and black. Polyamide and polyvinyl chloride were the common MP types in every specimen. The possible sources of MPs were fishing nets, ropes, and packaging material. This investigation points to MP contamination in aquatic ecosystems and particular species. It provides advanced knowledge of MP pollution, sources, and effects on regional ecosystems and public health.

Investigation the Effect of Thermal Agent on Physical Properties of PVC-PVA Blended

في هذه الدراسة , الخصائص البصرية لبولي فنيل كلورايد (PVC) و بولي فنيل الكحول (PVA) واغشية الخلائط بولي فنيل الكحول – بولي فنيل كلورايد الثنائية بتراكيز مختلفة (PVA75% + PVC25%, PVA50% + PVC50%, and PVA25% + PVC 75%) قد تم فحصها بالنسبه لدرجات الحرارة مختلفة (25, 120, 140) درجة سليزية لمدة ساعه واحدة. لقد تم تحضير اغشية الخلائط لبولي فنيل الكحول – بولي فنيل كلورايد الثنائية باستخدام طريقة الصب. مطيافية الاشعة المرئية–فوق البنفسجية سوف تستخدم لتعيين الخصائص البصرية لهذه الاغشية في مدى اطوال الموجية (200-900) نانومتر مثل النفاذية و امتصاصية ومعامل امتصاص و فجوة الطاقة وكذلك تأثير درجة الحرارة على هذه المعاملات. النتائج التى تم الحصول عليها من الجزء العملي تشير بان الامتصاصية ومعامل الامتصاص لخلائط بولي فنيل الكحول – بولي فنيل كلورايد الثنائية سوف تزداد مع زيادة تركيز بولي فنيل الكحول. فجوة الطاقة لخلائط بولي فنيل الكحول – بولي فنيل كلورايد الثنائية بتراكيز مختلفة سوف تقل مع زيادة تركيز بولي فنيل الكحول. يتميزنسبة الخليط الثنائي PVA 75%+ PVC25% بخصائص بصرية مناسبة للغايه. امتصاصية و معامل امتصاص لخلائط بولي فنيل الكحول – بولي فنيل كلورايد الثنائية سوف تزداد مع زيادة درجة الحراره في حين فجوة الطاقة والنفاذية لخلائط بولي فنيل الكحول – بولي فنيل كلورايد الثنائيه سوف تقل مع زيادة درجة الحرارة. طبيعة الأنتقالات الالكترونية لخلائط بولي فنيل الكحول – بولي فنيل كلورايد الثنائية بتراكيز مختلفة قبل و بعد تعرض للدرجات الحرارة هي غير مباشرة. من النتائج العلمية التي تم الحصول عليها يمكن الاستنتاج ان الامتصاصية و معامل الامتصاص لخلائط بولي فنيل الكحول – بولي فنيل كلورايد الثنائية هي أفضل من البوليمرات بولي فنيل الكحول وبولي فنيل كلورايد النقية. الخصائص البصرية لأغشية الخلائط بولي فنيل الكحول – بولي فنيل كلورايد الثنائية سوف تتأثر بتعرض الى درجات الحرارة.

An Electrochemical Study Using Experimental Design for the Determination of Prucalopride Succinate via the Optimized Ion Selective Electrode

Prucalopride succinate (PCP) was determined by potentiometry using an ion-selective electrode to obtain the most optimum ion-selective electrode. A screening study was carried out to determine the best membrane components, in which a PCP selective electrode was investigated with dioctyl phthalate as a plasticizer in a polymeric polyvinyl chloride polymeric matrix. Sensors were fabricated using phosphotungstic acid as an exchanger and β-cyclodextrin as an ionophore. Then, an optimization process was carried out, which involved the detection of significant factors affecting membrane response variables followed by the establishment of Box Behnken design in which levels of the selected factors, namely, percent of matrix, a ratio of plasticizer: polyvinyl chloride, and Log of soaking concentration were carefully selected (three levels for each factor). The optimized membrane was examined by measuring the slope, LOQ, linearity of PCP, and response time as response variables. Linear responses of PCP within the concentration ranges of 9.99 × 10−8−3.39 × 10−5 mol l−1 were obtained, and a slope of 61.591 ± 1.112 was observed. The selectivity coefficients of the developed sensors indicated excellent selectivity for PCP. The proposed sensor displayed useful analytical characteristics for the sensitive and selective determination of PCP.

Electric and dielectric responses of Au/n-Si structure by Mn doped PVC interfacial layers

This paper has investigated and compared the impact of polyvinyl chloride (PVC) without/with manganese (Mn) metallic nanoparticles interfacial layer on the electric and impedance characteristics of Schottky diode (SD) with a structure of Au/n-Si (MS). The structures of these two metal-polymer-semiconductor (MPS) SDs are Au/PVC/n-Si and Au/PVC:Mn/n-Si. A detailed description of the SDs manufacturing process is given. The x-ray diffraction (XRD) analysis, Scanning Electron Microscope (FE-SEM) images, and Electron Dispersive x-ray (EDX) spectroscopy are three methods that have been utilized to examine mean size of crystallite, morphology of surface, purity specification. The fundamental electronic variables of these devices are ascertained and contrasted with one another using the I-V characteristic measurement at ±6 V. Ohm’s law, Thermionic Emission (TE) theory, modified Norde, and Cheung functions are used to calculate the SDs’ leakage current (I0), ideality coefficient (n), potential barrier height (BH), shunt (Rsh), and series (Rs) resistances. Investigations are conducted on the energy dependence of surface states density (Nss) and the current conduction mechanisms (CCMs) for both reverse and forward biases. These interfacial layers are known to decrease the n, Rs, and Nss. The PVC polymer interlayer leads to improve the efficiency of the MS-type SD, but it does not when doped by Mn nanoparticles. Additionally, by measuring impedance at a bias of 1.5 V and 100 Hz-1 MHz frequency range, the frequency dependence of dielectric properties of the prepared SDs is studied. The dielectric permittivity, dielectric loss tangent, electronic modulus, and ac electronic conductivity of these SDs are all studied.

Argatroban- and copper-modified polymers with improved thromboresistance and antimicrobial properties

This paper describes a novel approach the development of biocompatible polyvinyl chloride (PVC) and polyurethane (PU) polymers, modified with copper (II) ions followed by the immobilisation the thrombin inhibitor argatroban (AG) using dopamine chemistry. The surface loading of the immobilised AG was 6.06 µg cm−2 on PVC and 6.66 µg cm−2 on PU, confirmed by FTIR and inhibitor concentration measurements. Both AG/Cu-modified polymers produced NO by catalytically decomposing S-nitrosothiol, reaching NO levels in plasma of 0.59 × 10–10molcm-2min-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{mol} \\, {\ ext{cm}}^{-2} \\, {\ ext{min}}^{-1}$$\\end{document} for AG/Cu-PVC and 0.51 × 10–10molcm-2min-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{mol} \\, {\ ext{cm}}^{-2} \\, {\ ext{min}}^{-1}$$\\end{document} for AG/Cu-PU, matching endothelial cell-produced physiological levels. This modification improved the haemocompatibility of the polymers through thrombin inhibition and reduced platelet aggregation and adhesion. Additionally, both modified polymers inhibited Staphylococcus aureus adhesion, growth and viability, confirming their acquired antibacterial properties. Antibacterial activity against Escherichia coli was also observed. These results demonstrate that modifying PVC and PU surfaces with copper (II) and AG produced materials with dual antithrombotic and antibacterial functions.Graphical abstract

Investigation of nano MgO loaded polyvinyl chloride polymer in protective clothing as a nonlead materials

Recently, investigation of advanced shielding materials to be used as an alternative to lead apron has become important. In the current study, MgO loaded into PVC matrix as a non-lead modern shielding composite was modeled to evaluate its performance on radiation protective clothing (RPC). Parameters such as mass attenuation coefficient (MAC), mean free path (MFP), flux buildup factor (FBF), transmission factor (TF) and lead equivalent value (LEV) of samples were calculated using MCNPX Code. The simulation of the MCNP code was validated, by comparing the mass attenuation of concrete sample, with standard XCOM data and very good agreement was attended between XCOM and MC Code results. The MAC of nano and micro-sized samples were also compared with pure PVC and it was found that the nano MgO particle exhibits higher attenuation compared to micro MgO particle and pure PVC. The results show that, the MAC of samples increased to 63.13 % in 1.332 MeV with increasing filler concentration of nano MgO to 50 wt% relative to pure PVC. Investigation of LEV shows that nano MgO sample has more effective than Pb in 1.173 and 1.332 MeV gamma ray energy so that it provides 36.46 % and 11.13 % lighter RPC than Pb ones.

Fabrication and adapting the optical, and dielectric performance of PVC/ MnFe2O4/ZnMn2O4 nanocomposite films for optoelectronic applications

The current study focuses on the fabrication of hybrid flexible polymers composed of MnFe2O4/ZnMn2O4 nanocomposites doped polyvinyl chloride (PVC). The doped polymers show great potential for utilization in a wide range of optoelectronics applications. PVC/(1-x)MnFe2O4/xZnMn2O4 were made using the casting and sol gel processes. The effect of (1-x)MnFe2O4/xZnMn2O4 nanocomposite samples on the optical parameters of PVC polymer has been explored using ultraviolet–visible diffused reflectance measurements. Doped polymers might be useful as protective barriers against ultraviolet radiation of various wavelengths (UVA, UVB, UVC) and as excellent absorber materials for solar cells. The direct and indirect bandgaps (Eg) of PVC are 4.26 and 4.08 eV. The direct/indirect optical band gap lowered to their lowest 3.97/3.45 eV as the PVC doped with nanofillers contained 50 %/80 % ZnMn2O4, respectively. Different models were used to extracted the refractive index (n) of different polymers based on the obtained optical band gaps (direct/indirect). Doped polymers containing 50 and 80 % ZnMn2O4 had the highest n values using direct and indirect Eg values, respectively. The n value (obtained from the direct optical bandgap energy) of PVC increased from 2.209 to the maximum value (2.262) as x = 0.5. The n value (obtained from the indirect optical bandgap energy) of PVC increased from 2.349 to the maximum value (2.367) as x = 0.8. All linear and nonlinear optical parameters of PVC polymer were improved as it doped with the nanocomposite fillers. The fluorescence (FL) intensity of PVC was reduced as it was doped with (1-x)MnFe2O4/xZnMn2O4 and this intensity reduced as the content of ZnMn2O4. The standard (CIE) color space chromaticity diagram was used to analysis the FL spectra for different samples. The effect of nanocomposite samples on the AC conductivity, dielectric constants and electric modulus of the PVC was studied. At 1 kHz, the dielectric constant of PVC was increased from 11.745 to 12.906 and 12.096 for polymers with x = 0 and x = 0.2, respectively. The enhanced optical and dielectric properties of the PVC/(1-x)MnFe2O4/xZnMn2O4 polymers nanocomposites suggest that these materials are suitable for smart electronic devices.

Sustainable strategies towards better utilization of synthetic polymers.

The abstract provides an overview of a study focused on analyzing diverse strategies to achieve sustainable utilization of synthetic polymers through effective waste management. The escalating global consumption of synthetic polymers has precipitated a concerning increase in plastic waste and environmental degradation. To address this challenge, novel materials with specified application goals, such as engineered plastic, have been developed and are intended for recycling and reuse. Despite the reuse and recycling, when plastic gets disposed into the environment, the degradation properties of plastics render a direct disposal hazard, posing a significant environmental threat. To mitigate these issues, the concept of replacing specific monomers of engineered synthetic plastics with bio-alternatives or blending them with other polymers to enhance sustainability and environmental compatibility has emerged. In this study, Acrylonitrile Butadiene Styrene (ABS) plastic is the focal material, and three distinct investigations were conducted. First, replacing ABS plastic's butadiene monomer with natural rubber was explored for its properties and environmental impact. Second, ABS plastic was blended with virgin, recycled, and bio-alternatives of PET (polyethylene terephthalate) and PVC (polyvinyl chloride) polymers. Lastly, recycled ABS blended with recycled PET and PVC was analyzed for mechanical properties. Comparative assessments of these blends were made based on mechanical properties, carbon emissions, and cost-effectiveness. The study determined that the r-ABS/r-PVC (recycled) blend exhibited the most favorable characteristics for practical application.

Microplastic profile in the sediment of Jakarta Bay estuary, Indonesia: Characterization based on size fraction and the potential risk to the ecosystem

Jakarta Metropolitan is known as the most populated and busiest city in Indonesia and among the top urban areas in the world with a common problem of solid and liquid waste. The present study aimed to assess the occurrence of microplastic (MP) pollution in sediment from the downstream rivers and coastal water of Jakarta Bay and estimate the potential risk to the ecosystem. Two composite sediment samples (river and coastal) were collected from the Jakarta Bay estuary. Distribution of sediment size showed that the medium size (100–500 µm) was the most dominant in river and coastal samples. Our finding demonstrated the highest MP concentration reported from the estuary ecosystem, i.e., 1184–1337 particles/100 g of river sediment and 804–1055 particles/100 g of coastal sediment. Classification based on size category revealed that the medium size (100–500 µm) was the most dominant MP in river sediment, while the smaller one (50–100 µm) was the most dominant MP in the coastal sediment. The present study indicates that terrestrial origin contributes to the MP pollution of Jakarta Bay. Polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET) were the most dominant polymers in the river and coastal sediments. The risk assessment of MP pollution in Jakarta Bay estuary potentially exhibits a very high risk to the ecosystem, primarily related to polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), and polyurethane (PU) polymers and the MP sizes.

Impact of a nanofiltration system on microplastic contamination in Geneva groundwater (Switzerland)

Microplastics (MPs) have been observed in the oceans, fresh waters, karstic water and remote water bodies. However, little is known on groundwater contamination, which is a natural resource of utmost importance for millions of people and is often perceived as a reliable source of water. Moreover, nanofiltration is perceived as a reliable technology to remove contaminants from water. In this study, large sample volumes of a silty-sandy gravel aquifer and the corresponding nanofiltered water were analysed for the presence of MPs (> 20 µm) using Fourier transform infrared (FTIR) microscopy. Concentration in ground water was 8 ± 7 MPs/m3 and increased to 36 ± 11 MPs/m3 in nanofiltered water. All MPs had a maximum Ferret diameter lower than 500 µm. Size distribution of MPs was towards the small size class (20–50 µm). In groundwater, 33% of MPs were detected in the smallest size class (20–50 µm) and 67% in the 50–100-µm-size class. In comparison, around 52% of MPs in nanofiltered water were observed in the 20–50 µm size class. Moreover, 33% of the MPs observed in nanofiltered water were in the 50–100 µm size class and 15% in the 100–500-µm-size class. From a chemical point of view, different plastic polymers were identified in groundwater and in nanofiltered water, such as polypropylene (PP), polyvinyl chloride (PVC), ethylene (vinyl acetate) copolymer (EVA), polyethylene (PE), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA) and other polymer materials (such as polystyrene-based copolymers, vinyl-based copolymers). Fibres were observed in all samples, but only a small number of fibres (near 1%) were identified as PP synthetic fibres in nanofiltered water. Furthermore, no clear difference of fibre concentrations was observed between groundwater (232 ± 127 fibres/m3) and nanofiltered water (247 ± 118 fibres/m3). Groundwater had extremely low levels of microplastics, and although the nanofiltration effectively removes suspended particulate matter, it slightly contaminates the filtered water with MPs.

Design and application of supramolecular based solid-contact ion-selective electrode for selective green determination of tenofovir disoproxil fumarate

This work describes the fabrication of solid-contact potentiometric sensor to determine the antiviral drug; tenofovir disoproxil fumarate. Screen-printed carbon electrodes have been selected as being a disposable substrate material. Ion sensing membrane is based on Polyvinyl chloride (PVC) polymer that was impregnated with calix [6] arene as being an ionophore for facilitating transferring the drug of interest from the sample phase into the membrane phase through decreasing Gibbs free energy of transfer. We applied a graphene nanocomposite interlayer between the carbon substrate and the polymeric membrane for overcoming potential drift, which is commonly encountered in solid-contact potentiometric sensors. As a result, the graphene nanocomposite layer enhanced the sensor performance and stabilized the potential signal as compared to the control sensor. The sensor performance characteristics were studied according to International Union of Pure and Applied Chemistry (IUPAC) recommendations, and linear range has been 0.01 M - 10 μM with limit of detection (LOD) 7.3 μM. We utilized the sensor for inline determination of the release of tenofovir disoproxil fumarate from its tablet pharmaceutical formulation without any separation or sample pre-treatment steps. In an attempt to be eco-friendly through evaluating the suggested method regarding its greenness, the method has been found to be excellent green according to the eco scale method.

A Review Study on the Improving the Hot Mixture Asphalt Properties by Using Different Types of Polymers as Additive for Asphalt Material

By integrating the design of high-performance material with solid structural design, flexible pavement performance can be increased and the service life extended. In the context of creating highways the topic of asphalt polymer modification and the incorporation of polymers in asphalt material by mechanical mixing or chemical reaction, has received substantial scholarly coverage. A wide range of polymers types are used in the method of changing asphalt material and subsequently enhancing hot mixed asphalt. The main objective of this paper is to review prior research on employing polymer materials to develop the qualities of asphalt cement and hot mixed asphalt. This study reviews three different types of polymers. These polymers are Styrene-butadiene-styrene (SBS), polytetrafluoroethylene (PTFE), and polyvinyl chloride polymers (PVC). According to earlier studies in this area, these polymers are elastomers and plastomers that are utilized to enhance the mechanical properties of hot-mix asphalt while also increasing the stability, elasticity, and stiffness of asphalt binders. The overall performance of asphalt pavement can be achieved by reducing the possibility of rutting in the summer and cracking in the winter.

Paper-Based Archives Encapsulation: Identifying Physical-Mechanical and Chemical Materials

The FTIR test results show mylar plastic sample is a polybutylene terephthalate polymer. Laraska 1, laraska 2 and laraska 3 plastic samples are polyvinyl alcohol polymers. Mika Asahi and Astralon Restorasi 1 plastic samples are polyvinyl chloride polymers. The plastic samples of Astralon Restorasi 2, Astralon Restorasi 3 and Plastik Sablon are poly (cyclohexadimethylene) terephthalate polymer. 3M double-sided tape samples are Cellulose Acetate-Based Backing Tapes and Acrylic Based Adhesive Tapes, kenko, joyco and subaru double-sided tape samples are Polypropylene-Based Backing Tapes and Rubber (Synthetic) Based Adhesive Tapes. There was an increase in MD direction tear strength values after aging in Mylar (50.67%), Plastik Sablon (11.58%), Mika Asahi (21.12%), Astralon Restorasi 1 (24.02), and Astralon Restorasi 3 (34.87%) samples and a decrease in Astralon Restoration 2 (3.27%) samples. There was an increase in tear strength values in the CD direction for Mylar (20.67%), Mika Asahi (15.14%), Astralon Restorasi 1 (30.26%), Astralon Restorasi 2 (27.01%) and Astralon Restorasi 3 (4.37%) and a decrease for Plastik Sablon samples (32.59%). There was an increase in tensile strength values after aging in Mylar (4.30%), Plastik Sablon (10.43%), Mika Asahi (5.42%) and Astralon Restorasi 3 (1.67%) samples and a decrease in Astralon Restorasi 1 (2.39%) and Astralon Restorasi 2 (5.84%) samples. GC-MS testing on all double-sided tape samples obtained the most dominant content results are Oxirane, 2-ethyl-2-methyl-, Cyclopentane, methyl- and 3-methylpentane.

Ionophore-Based Polymeric Sensors for Potentiometric Assay of the Anticancer Drug Gemcitabine in Pharmaceutical Formulation: A Comparative Study.

Gemcitabine is a chemotherapeutic agent used to treat various malignancies, including breast and bladder cancer. In the current study, three innovative selective gemcitabine hydrochloride sensors are developed using 4-tert-butylcalix-[8]-arene (sensor 1), β-cyclodextrin (sensor 2), and γ-cyclodextrin (sensor 3) as ionophores. The three sensors were prepared by incorporating the ionophores with o-nitrophenyl octyl ether as plasticizer and potassium tetrakis(4-chlorophenyl) borate as ionic additive into a polyvinyl chloride polymer matrix. These sensors are considered environmentally friendly systems in the analytical research. The linear responses of gemcitabine hydrochloride were in the concentration range of 6.0 × 10-6 to 1.0 × 10-2 mol L-1 and 9.0 × 10-6 to 1.0 × 10-2 mol L-1 and 8.0 × 10-6 to 1.0 × 10-2 mol L-1 for sensors 1, 2, and 3, respectively. Over the pH range of 6-9, fast-Nernst slopes of 52 ± 0.6, 56 ± 0.3, and 55 ± 0.8 mV/decade were found in the same order with correlation regressions of 0.998, 0.999, and 0.998, respectively. The lower limits of detection for the prepared sensors were 2.5 × 10-6, 2.2 × 10-6, and 2.7 × 10-6 mol L-1. The sensors showed high selectivity and sensitivity for gemcitabine. Validation of the sensors was carried out in accordance with the requirements established by the IUPAC, while being inexpensive and easy to use in drug formulation. A statistical analysis of the methods in comparison with the official method showed that there was no significant difference in accuracy or precision between them. It was shown that the new sensors could selectively and accurately find gemcitabine hydrochloride in bulk powder, pharmaceutical formulations, and quality control tests. The ionophore-based sensor shows several advantages over conventional PVC membrane sensor sensors regrading the lower limit of detection, and higher selectivity towards the target ion.

Degree of Wettability and Aging of PVC and PET Polymers Treated by Plasma Immersion or Deposition

The wettability, aging characteristics, and optical transmittance in the visible region following Plasma Immersion (PI) or Plasma Immersion Ion Implantation (PIII) treatment of polymers were studied. In addition, structural and chemical modifications of the polymers were examined. The polymers investigated were white Polyvinyl chloride (PVC) and Polyethylene terephthalate (PET). Initially, plasmas of nitrogen (N2) were employed, aiming to produce hydrophilic surfaces. In contrast, sulfur hexafluoride (SF6) plasma treatments produce high surface fluorination, which tends to increase hydrophobicity. Isopropyl alcohol (IPA) was mixed with SF6 or N2 to deposit a series of organic films. Aging effects over 30 days on the contact angle, q, were measured for the polymer surfaces. Conventional plasma immersion (PI) tended to decrease of θ for N2 plasma treatments, with or without IPA, and to increase θ values ​​for samples immersed in IPA/SF6 plasma. The highest value of θ was 140º for IPA/SF6 plasma treatments, while the smallest θ was 20º for N2 or IPA/N2 treatments. There was an ideal condition under which θ was stable upon aging. The results obtained suggest the developed treatment enables the preparation of polymers with distinct wettability properties depending of the nature of the plasma with overall reasonable aging stability. Moreover, the opaque character of these materials makes them interesting for the production of bags, boxes, bottles, food packaging, among others.

Optimizing Eco-Friendly Degradation of Polyvinyl Chloride (PVC) Plastic Using Environmental Strains of Malassezia Species and Aspergillus fumigatus.

Worldwide, huge amounts of plastics are being introduced into the ecosystem, causing environmental pollution. Generally, plastic biodegradation in the ecosystem takes hundreds of years. Hence, the isolation of plastic-biodegrading microorganisms and finding optimum conditions for their action is crucial. The aim of the current study is to isolate plastic-biodegrading fungi and explore optimum conditions for their action. Soil samples were gathered from landfill sites; 18 isolates were able to grow on SDA. Only 10 isolates were able to the degrade polyvinyl chloride (PVC) polymer. Four isolates displayed promising depolymerase activity. Molecular identification revealed that three isolates belong to genus Aspergillus, and one isolate was Malassezia sp. Three isolates showed superior PVC-biodegrading activity (Aspergillus-2, Aspergillus-3 and Malassezia) using weight reduction analysis and SEM. Two Aspergillus strains and Malassezia showed optimum growth at 40 °C, while the last strain grew better at 30 °C. Two Aspergillus isolates grew better at pH 8-9, and the other two isolates grow better at pH 4. Maximal depolymerase activity was monitored at 50 °C, and at slightly acidic pH in most isolates, FeCl3 significantly enhanced depolymerase activity in two Aspergillus isolates. In conclusion, the isolated fungi have promising potential to degrade PVC and can contribute to the reduction of environmental pollution in eco-friendly way.

Microplastics Distribution within Western Arctic Seawater and Sea Ice.

Microplastic pollution has emerged as a global environmental concern, exhibiting wide distribution within marine ecosystems, including the Arctic Ocean. Limited Arctic microplastic data exist from beached plastics, seabed sediments, floating plastics, and sea ice. However, no studies have examined microplastics in the sea ice of the Canadian Arctic Archipelago and Tallurutiup Imanga National Marine Conservation Area, and few have explored Arctic marginal seas' water column. The majority of the microplastic data originates from the Eurasian Arctic, with limited data available from other regions of the Arctic Ocean. This study presents data from two distinct campaigns in the Canadian Arctic Archipelago and Western Arctic marginal seas in 2019 and 2020. These campaigns involved sampling from different regions and matrices, making direct comparisons inappropriate. The study's primary objective is to provide insights into the spatial and vertical distribution of microplastics. The results reveal elevated microplastic concentrations within the upper 50 m of the water column and significant accumulation in the sea ice, providing evidence to support the designation of sea ice as a microplastic sink. Surface seawater exhibits a gradient of microplastic counts, decreasing from the Chukchi Sea towards the Beaufort Sea. Polyvinyl chloride polymer (~60%) dominated microplastic composition in both sea ice and seawater. This study highlights the need for further investigations in this region to enhance our understanding of microplastic sources, distribution, and transport.

Micro- and nanoplastics (MNPs) and their potential toxicological outcomes: State of science, knowledge gaps and research needs

Plastic waste has been produced at a rapidly growing rate over the past several decades. The environmental impacts of plastic waste on marine and terrestrial ecosystems have been recognized for years. Recently, researchers found that micro- and nanoplastics (MNPs), micron (100 nm – 5 mm) and nanometer (1 – 100 nm) scale particles and fibers produced by degradation and fragmentation of plastic waste in the environment, have become an important emerging environmental and food chain contaminant with uncertain consequences for human health. This review provides a comprehensive summary of recent findings from studies of potential toxicity and adverse health impacts of MNPs in terrestrial mammals, including studies in both in vitro cellular and in vivo mammalian models. Also reviewed here are recently released biomonitoring studies that have characterized the bioaccumulation, biodistribution, and excretion of MNPs in humans. The majority MNPs in the environment to which humans are most likely to be exposed, are of irregular shapes, varied sizes, and mixed compositions, and are defined as secondary MNPs. However, the MNPs used in most toxicity studies to date were commercially available primary MNPs of polystyrene (PS), polyethylene (PE), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and other polymers. The emerging in vitro and in vivo evidence reviewed here suggests that MNP toxicity and bioactivity are largely determined by MNP particle physico-chemical characteristics, including size, shape, polymer type, and surface properties. For human exposure, MNPs have been identified in human blood, urine, feces, and placenta, which pose potential health risks. The evidence to date suggests that the mechanisms underlying MNP toxicity at the cellular level are primarily driven by oxidative stress. Nonetheless, large knowledge gaps in our understanding of MNP toxicity and the potential health impacts of MNP exposures still exist and much further study is needed to bridge those gaps. This includes human population exposure studies to determine the environmentally relevant MNP polymers and exposure concentrations and durations for toxicity studies, as well as toxicity studies employing environmentally relevant MNPs, with surface chemistries and other physico-chemical properties consistent with MNP particles in the environment. It is especially important to obtain comprehensive toxicological data for these MNPs to understand the range and extent of potential adverse impacts of microplastic pollutants on humans and other organisms.

Occurrence and dynamics of microplastics and emerging concern microparticles in coastal sediments: Impact of stormwater upgrade and port-associated facilities

Urban runoff is a significant source of microplastic pollution in aquatic environments, especially in coastal areas. Despite urban stormwater runoff being considered a major pathway of anthropogenic particles there's no studies about the impact of stormwater upgrades on microparticle transport. Moreover, due to the influence of anthropogenic activities, including maritime traffic and maintenance, on coastal environments, it is crucial to identify plastic debris from both inland and in-shore sources. This study evaluates characteristics, abundance, and distribution of microplastics in subtidal sediments from the southwestern Atlantic region, influenced by a recently upgraded stormwater outfall and port facilities. Herein, we have analyzed temporal trends, including seasonal dynamics and their relation with the pre- and post-upgrade of the stormwater outfall. Three main types of anthropogenic microparticles were observed: common plastic (MPs), paints (Pps), and tire wear particles (TWPs). Microparticle groups varied in morphology, color, and size distribution, including uncommon microparticle debris. Analysis by FTIR and Raman spectroscopies allows the identification of polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, polystyrene, polyamide, and polyacrylonitrile polymers for MPs mainly. Pigments such as Naphthol AS, phthalocyanine, and quinacridone have been identified in Pps. SEM-EDS and FTIR analysis of collected TWPs revealed similar trace metals constituents and infrared signals to those observed in tire road samples. Spatial and temporal abundances of microparticle groups were significantly different (p < 0.05), mainly related to the distance from the stormwater outfall and seasons. TWPs showed the most significant seasonal increment rate among pre and post-upgrade periods. Furthermore, the upgrades made to the stormwater system have been observed to intensify the transport and increase the presence of specific anthropogenic microparticles in subtidal sediments. Based on these findings, the occurrence of TWPs emerges as a reliable urban runoff indicator to differentiate ex and in-situ sources in multipolluted coastal environments.